Semiconductor device and method of manufacturing semiconductor device

Abstract

A semiconductor device that can be miniaturized or highly integrated can be provided. The semiconductor device includes a first conductor positioned over a substrate; an oxide positioned in contact with atop surface of the first conductor; a second conductor, a third conductor, and a fourth conductor positioned over the oxide; a first insulator in which a first opening and a second opening are formed, the first insulator being positioned over the second conductor to the fourth conductor; a second insulator positioned in the first opening; a fifth conductor positioned over the second insulator; a third insulator positioned in the second opening; and a sixth conductor positioned over the third insulator. The third conductor is positioned to overlap with the first conductor. The first opening is formed to overlap with a region between the second conductor and the third conductor. The second opening is formed to overlap with a region between the third conductor and the fourth conductor.

The invention claimed is: 
     
       1. A semiconductor device comprising:
 a first conductor positioned over a substrate; 
 an oxide positioned in direct contact with a top surface of the first conductor; 
 a second conductor, a third conductor, and a fourth conductor positioned over the oxide; 
 a first insulator in which a first opening and a second opening are formed, the first insulator being positioned over the second conductor to the fourth conductor; 
 a second insulator positioned in the first opening; 
 a fifth conductor positioned over the second insulator; 
 a third insulator positioned in the second opening; and 
 a sixth conductor positioned over the third insulator; insulator, 
 wherein the third conductor is positioned to overlap with the first conductor, 
 wherein the first opening is formed to overlap with a region between the second conductor and the third conductor, and 
 wherein the second opening is formed to overlap with a region between the third conductor and the fourth conductor. 
 
     
     
       2. The semiconductor device according to  claim 1 ,
 further comprising a first capacitor and a second capacitor, 
 wherein the first capacitor is electrically connected to the second conductor, and 
 wherein the second capacitor is electrically connected to the fourth conductor. 
 
     
     
       3. The semiconductor device according to  claim 2 ,
 wherein the first capacitor is positioned over the second conductor, and 
 wherein the second capacitor is positioned over the fourth conductor. 
 
     
     
       4. The semiconductor device according to  claim 1 ,
 wherein the first conductor is connected to a wiring provided below the first conductor. 
 
     
     
       5. The semiconductor device according to  claim 1 ,
 wherein the second insulator is in contact with a top surface of the oxide and a side surface of the first insulator, and 
 wherein the third insulator is in contact with the top surface of the oxide and the side surface of the first insulator. 
 
     
     
       6. The semiconductor device according to  claim 1 ,
 wherein the oxide comprises a first oxide and a second oxide over the first oxide, 
 wherein the first oxide and the second oxide each comprise indium, an element M (M is one or more selected from gallium, aluminum, yttrium, and tin), and zinc, and 
 wherein an atomic ratio of indium to the element M in the first oxide is lower than an atomic ratio of indium to the element M in the second oxide. 
 
     
     
       7. A method of manufacturing a semiconductor device, comprising the steps of:
 forming a first conductor over a substrate; 
 depositing an oxide film in direct contact with a top surface of the first conductor; 
 depositing a first conductive film over the oxide film; 
 forming an oxide and a second conductor by processing the oxide film and the first conductive film into an island shape; 
 forming a first insulator covering the oxide and the second conductor; 
 removing parts of the first insulator to form a first opening and a second opening each overlapping with the second conductor; 
 removing parts of the second conductor that overlap with the first opening and the second opening to form a third conductor, a fourth conductor, and a fifth conductor, the fourth conductor being positioned to overlap with the first conductor; 
 exposing regions of the oxide that do not overlap with the third conductor, the fourth conductor, and the fifth conductor; 
 depositing a first insulating film in contact with a top surface of the oxide; 
 performing microwave treatment in an atmosphere comprising oxygen; 
 depositing a second conductive film over the first insulating film; and 
 forming a second insulator and a sixth conductor in the first opening and forming a third insulator and a seventh conductor in the second opening by performing a polishing treatment on the first insulating film and the second conductive film until a top surface of the first insulator is exposed. 
 
     
     
       8. The semiconductor device according to  claim 1 ,
 wherein the second insulator is in contact with a top surface of the oxide and an inner surface of the first opening, and 
 wherein the third insulator is in contact with the top surface of the oxide and an inner surface of the second opening.